The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 16, 1989
Filed:
Nov. 12, 1986
Applicant:
Inventor:
Steven H Drucker, Oakland, CA (US);
Assignee:
Quential, Inc., Berkeley, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G06K / ;
U.S. Cl.
CPC ...
250566 ; 235462 ; 235472 ;
Abstract
A scanning device and method for reading bar-code or other contrasting marks from a surface at variable distance from the scanning device operates by modulating the focal point of the optical system to yield pulse responses on detected code bars while in focus, and average background response levels from the bar-code surface while out of focus. Modulation of focal point of the optical system is achieved in selected ways such as by positioning optical elements using piezoelectric or electromagnetic drivers or liquid-crystal elements, or by staggering the positions along an optical axis of arrays of optical sensors, or of optical fibers coupled to the sensors.